Somewhere earlier, cleanflametrap (Art) had a good suggestion of running a metal feeler gauge through the distributor sensor gap to trigger the coil. I think all you need to do is pull the disti cap...

^^^ Thanks John, that really helps make sense of the conflicting info I've seen -- why the flame trap housing with split big/small nipples is listed for B21FT, and why my old one had the small nipple...

If you're just trying to test the coolant temp sensor, measure the resistance between the ect pin and a ground pin, at the connector, with connector unplugged and key off, and compare it to the chart...